Die casting machine



y 1931- A. s. KIDD 1,815,776

DIE CASTING MACHINE I Filed May 27, 1929 Patented July 21, 1931 A UNITEDSTATES PAT-E NT OFFICE ALVIN STMEON KIDD, F MADISON, WISCONSIN, ASSIGNORTO MADISON -KIPP CORPORA- TION, 0F MADISON, WISCONSIN, A CORPORATION OFWISCONSIN ma casrme mcnnm Application filed Kay 27, 1929. Serial N0.866,447.

This invention relates to die casting ma chines and particularly to thegoose neck or llaidle which" delivers the molten metal to the '6'. Inthe operation of machines of this type the ladle or goose neck is raisedfrom the molten metal pot so that its discharge nozzle is brought.against either the die or a nozzle plate associated therewith. Air underpressure. or other equivalent means. is then rendered effective todisplace a part of. the molten metal from the goose neck ormetal-delivering chamber into the die cavity. Atthe termination of suchaction the ladle or goose neck is lowered into the metal pot.

The movements of the goose neck common- 1y cause a surging motion of themolten metal in the goose neck and at times this results in asuddendischarge or spurting of molten metal from the nozzle while the latteris out of contact with the die. This discharge often occurs withsufiicient force to throw the molten metal onto the nozzle plate, or thelower face of the die. or even into the'die itself, where it freezes.ll'hen this occurs it is commonly necessary to shut down the machine andclean the metal ofi.

The present invention checks such discharging action and comprises thefeatures described and shown in the accompanying drawings and indicatedby the claims.

In the drawings,

Fig. 1 is a side elevation, partly in section, of a portion of a diecasting machine showing a goose neck embodying my invention.

gigc2 is an enlarged view in section of the go se neck nozzle in itspreferred form.-

Figs. 3-and 1 are similar views of modified forms in which the nozzleportion of the goose neck may be made.

Referring to Fig. 1 of the drawings, 5 indicates the furnace of a diecasting machine upon which is supported the melting pot- 6. The gooseneck or pressure chamber is indicated at 7, being suspended within themelting pot- 6 and pivoted at 8 upon bracket 9. The goose neck 7 isprovided with an air nozzle 11 which contacts and establishes airconnection with the air chamber nozzle seat 12 for the purpose ofadmitting air imder pressure to the goose neck. At 13 is the air chamberwhich receives its air supply from any suitable source (not shown).

At the other end the ladle or goose neck includes a slender taperingspout or neck terminating in a nozzle 14. This nozzle rises and contactsnozzle plate 15 when the ladle is moved or rocked to raise the spoilt,such movement being accomplished by mechanism,

parts of which are shown in the drawings,

and whose exact form is immaterial to t present invention.

In Figs. 1 and 2, which illustrate the preferred form of the invention.there is shown agoose neck nozzle. the exterior configuration of whichis substantially the same as those at present in use. This nozzle isprovided with the usual seating flange 15 which seats upon the exteriorrim surrounding the mouth of the goose neck as indicated at 16. Thenozzle is provided with a passage 17 preferably tapered toward its upperend. This passage, as shown, does not extend entirely through thenozzle, but terminates short of the lower end leaving a thickness ofmetal to form a baffle 18. Through this bafile 18 and connecting thepassage 17 with the interior of the goose neck proper, is a secondpassage 19 which, as shown, is substantially one half the diameter ofthe lower end of passage 17. This enters angle.

It is to be understood that while the form of the goose neck nozzleabove describedis preferred, changes in the shape, size andproportioning may be made within the scope of the invention. Forexample, the forms shown in Figs. 3 and 4 may be used.

In Fig. 3 a single restricting passage 21 axially alined with passage 17is shown, thus permitting the molten metal to enter passage 17 in anaxial direction.

In Fig. 4 a plurality of still smaller passages 22 are shown in place ofa single passage. These serve to discharge the metal against the taperedbore of the nozzle.

It is also to be understood that while there is shown and described aspecific form of goose neck or pressure chamber and associatedmechanism, other forms are equally susceppassage 17 at approximately a Itible to the application of this invention.

In the form shown air pressure is utilized in displacing the moltenmetal from the goose neck, this being a familiar and satisfactorymethod. It might be desirable, however, under some conditions to useother pressure fluids for this purpose, or to use known displacing meansnot dependent on the use of fluid pressure. With such forms the presentinvention would be effective. It is not essential that the nozzle be aseparate piece from the goose neck, but such construction facilitatesreplacements, and as the nozzles have a shorter life than the gooseneck, results in economy. When the nozzle is formed as a separate,removable part of the goose neck, baffle 18 may be located in thenozzle, in the goose neck proper, or between these parts. If the nozzleis to form an integral part of the goose neck, in accordance with theearlier practice, it is necessary only that the baffle be locatedproperly in the metal-discharging or nozzle portion of the goose neckbore in orderto check eflectually the undesirable Spurting-0rdischarging action of the metal. While theexactcause for the desirableresults secured is immaterial to the invention, it is believed to be asfollows: I

When a considerable mass of molten metal surges toward the nozzle of thegoose neck, and this is apt to occur when the nozzle moves downward, theflow of the metal is checked as theadv'ancing wave of metal flows intothe neck and approaches the nozzle. At

such time the momentum of the metal is gradually converted into apressure-head. In the old type of nozzle and particularly in that commontype having a simple tapered bore, this pressure head is converted int arelatively high velocity head without substantial loss of energy,because the change of cross section of the passage through which themetal flows is gradual. Consequently the metal spurts from the nozzlewith considerable velocity. With the formsof nozzle shown in Figs. 1 and2 there is a sudden change of cross-section of the passage when themetal enters and again when it leaves the passage 19. The same actionoccurs with reference to the passage 21 of Fig. 3 and passages 22 ofFig. 4. The result is violent eddy flow, which absorbs the pressure headand thus limits the derived velocity head. Furthermore, in the forms ofFigs. 1, 2 and 4, the metal is discharged against the walls of thetapered passage 17, with an increased eddying and energy absorption.

The combined actions of suddenly reducing the flow path of the metal andthen suddenly increasin it, have been found to produce most eflicientresults. However, it is conceivable that the feature of suddenlyincreasing the flow path with the resultant dissipation of the force ofthe metal stream might be used alone.

Whatever the theory, the effect is to suppress the spurting to a degreewhich eliminates all harmful action.

What is claimed is,-

1. A metal-delivering pressure chamber for die casting machines, saidpressure chamber having a bore leading to a metal discharge port and aconstriction in said bore formed to effect an abrupt contraction and anabrupt expansion of the flow path of the I metal.

2. A pressure chamber for use in die casting machines of the type inwhich the metal containing pressure chamber is moved While disconnectedfrom the die, said pressure chamber having a bore leading to a metaldischarge port and a constriction in said bore formed to effect anabrupt contraction and an abrupt expansion of the flow path of themetal.

3. A metal-delivering pressure chamber for die casting'machine, saidpressure chamber having a bore leading to a metal discharge port; andmeans in the bore for producing a sudden decrease and then a suddenincrease in the cross sectional area of the flow path of the metalthrough said bore.

4;. A metal-delivering pressure chamber for die casting machines, saidpressure chamber having a bore leading to a metal discharge port and aconstriction in said bore formed to efl'ect an abrupt decrease and crosssectional area of the metal flow path therethrough.

6. A metal-delivering pressure chamber for die casting machines, saidpressure chamber having a bore leading to a metal dlscharge port; and abathe in said bore havmg a plurality of openings therein for the passageof metal to the discharge port, said baffle serving to effect an abruptincrease in the cross sectional area of the metal flow path on thedischarge side of the baflie.

7 a A pressure chamber for die casting maleading to a metal dischargeport and an annular bafile located in said bore forwardly of thedischarge port and having its sides dlsposed substantially at rightangles to the axis of the bore.

8. metal-delivering pressure chamber for d1e casting machines, saidpressure chamber having a bore leading to a metal discharge port and aconstriction in said bore formed to effect an abrupt decrease and thenan abrupt increase in the cross sectional area of the flow path of themetal and to direct 'the metal "towards the discharge port obliquely tothe axis of the bore.

9. A metal-delivering pressure chamber for die casting machines, saidpressure chamber having a bore leading to a metal discharge port and abaflle arranged in the bore to produce an abrupt contraction and anabrupt expansion of the metal flow path together with abrupt changes ofdirection 10. A metal-delivering pressure chamber for die castingmachines, said pressure chamber having a bore which includes ametal-containing portion and a contracting element for die castingmachines,

tapered portion leading toa port through which the metal is discharged;and a baflle intermediate said metal-containing and tapered portions ofthe bore for efi'ecting first a sudden reduction and then a suddenexpansion of the cross sectional area of the metal flow path through thebore.

11. A demountahle metal discharge nozzle of the type including ashiftable metal delivering pressure chamber, said nozzle having a boreleading to a port through which the final metal discharge takes place,and the inner end of the nozzle being closed by a wall having an inletport for effecting a sudden expansion of the metal flow path through thenozzle.

12. A demountahle metal discharge nozzle element for die ca tingmachines, of the type including a shifta le ladle, said nozzle having acontracting tapered bore through which the final discharge takes place,and an ehtrance passage coaxial with said bore and of an area materiallysmaller than the large end of said bore.

13. A demountahle metal discharge nozzle 4 element for die castingmachines, of the t including a shiftable ladle, said nozzle having acontracting tapered bore through which the final discharge takes place,and a constricted entrance passage to said bore arranged to direct theentering metal against the side walls of said tapered passage.

14. A demountahle-metal discharge nozzle element for die castingmachines, of the type including a shiftable ladle, said nozzle having acontracting tapered bore through which the final discharge takes place,and a plurality of entrance passages to said bore approximately tangentwith the periphery of the larger end of said tapered bore.

In testimony whereof I have signed my name to this specification.

ALVIN SIMEON KIDD.

